Macrostructural unit having a catalytically-active zeolite surface

Abstract

Macrostructural units of various shapes and forms having a catalytically-active zeolite surface particularly useful in catalyzing hydrocarbon conversion reactions are prepared by: (a) mixing a slurry containing one or more of finely divided silicon, silica gel, alumina, aluminum hydroxide and kaolin, and having the desired ratio of silicon atoms to aluminum atoms, with plasticizer to form a plastic mass; (b) shaping the plastic mass to a desired configuration; (c) calcining the shaped plastic mass at 500° to 800° C. for 1 to 10 hours to form a rigid macrostructural unit having the same configuration as the shaped plastic mass; (d) crystallizing 5 to 80% of the rigid macrostructural unit obtained by calcination to crystalline aluminosilicate zeolite; and, (e) activating the crystalline aluminosilicate zeolite to catalytically-active zeolite.

We claim: 
     
       1. A process for preparing a macrostructural unit having a catalytically-active zeolite surface as an integral part of the macrostructural unit, which comprises: (a) mixing a slurry containing one or more of finely divided silica, silica gel, alumina, aluminum hydroxide and kaolin, said slurry having a ratio of silicon atoms to aluminum atoms corresponding to that of the zeolite to be formed, with plasticizer to form a plastic mass;   (b) shaping the plastic mass to a desired configuration;   (c) calcining the shaped plastic mass at 500° to 800° C. for 1 to 10 hours to form a rigid macrostructural unit having the same configuration as the shaped plastic mass;   (d) crystallizing 5 to 80% of the rigid macrostructural unit obtained by calcination to crystalline aluminosilicate zeolite; and,   (e) activating the crystalline aluminosilicate zeolite to catalytically-active zeolite.   
     
     
       2. A process according to claim 1, wherein 10 to 60% of the rigid macrostructural unit obtained by calcination is crystallized. 
     
     
       3. A process according to claim 1, wherein the rigid macrostructural unit is crystallized by dipping into a crystallizing solution under hydrothermal conditions. 
     
     
       4. The macrostructural unit having a catalytically-active zeolite surface prepared by the process of claim 1. 
     
     
       5. A macrostructural unit according to claim 4, having a hollow center. 
     
     
       6. A macrostructural unit according to claim 5, in the form of a cylinder. 
     
     
       7. A macrostructural unit according to claim 5, in the form of a hollow tube. 
     
     
       8. A macrostructural unit according to claim 5, in the form of an open-ended hollow rectangular block. 
     
     
       9. A macrostructural unit according to claim 7, wherein the hollow tube is present in a bundle of hollow tubes.